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Ian W Hunter - One of the best experts on this subject based on the ideXlab platform.

  • delivery of immunoreactive antigen using a controllable needle free Jet Injector
    Journal of Controlled Release, 2017
    Co-Authors: Catherine N. Hogan, Melis N Anahtar, Andrew J Taberner, Ian W Hunter
    Abstract:

    Abstract Intradermal immunization of mice against hepatitis B surface antigen (HBsAg) using a novel real-time controlled Jet Injector was assessed by comparison with intradermal and subcutaneous injection of antigen using a 27G needle and syringe. Three doses of aluminium-absorbed HBsAg were delivered at 0, 14, and 28 days. Antibodies to HBsAg were detected only in mice injected with antigen with antibody levels increasing with secondary injections. Mice vaccinated by intradermal injection using the Jet Injector or subcutaneous needle injection exhibited comparable immune responses at day 47. Differences in titer observed between intradermal Jet injected and needle injected animals reflect differences in the volume of antigen delivered. With the exception of minor bleeding at the injection site in a few animals injected either by Jet injection or needle, no adverse events were observed in any of the mice used in the study.

  • Analysis of Moving-Coil Actuator Jet Injectors for Viscous Fluids
    IEEE Transactions on Biomedical Engineering, 2016
    Co-Authors: Rhys Matthew James Williams, Bryan P. Ruddy, Catherine N. Hogan, Ian W Hunter, Poul M. F. Nielsen
    Abstract:

    Objective: A Jet Injector is a device that can be used to deliver liquid drugs through the skin using a fluid Jet, without the use of a needle. Most Jet Injectors are designed and used for the delivery of inviscid liquids, and are not optimized for the delivery of viscous drug compounds. To better understand the requirements for delivering viscous drugs, we have developed a mathematical model of the electromechanics of a moving-coil actuated Jet Injector as it delivers viscous fluids. Methods: The model builds upon previous work by incorporating the nonlinear electrical properties of the motor, compliant elements of the mechanical piston and ampoule system, and the effect of viscosity on Injector characteristics. The model has been validated by monitoring the movement of the piston tip and measurements of the Jet force. Results: The results of the model indicate that the Jet speed is diminished with increasing fluid viscosity, but overshoot and ringing in the Jet speed is unaffected. However, a stiffer ampoule and piston will allow for a better control of the Jet speed profile during an injection, and reduce ringing. Conclusion: We identified that the piston friction coefficient, the compliance of the Injector components, and the viscous properties of the fluid are important determinants of performance when Jet-injecting viscous fluids. Significance: By expanding upon previous Jet Injector models, this study has provided informative simulations of Jet Injector characteristics and performance. The model can be used to guide the design of future Jet Injectors for viscous fluids.

  • adaptive controller for a needle free Jet Injector system
    International Conference of the IEEE Engineering in Medicine and Biology Society, 2015
    Co-Authors: Ashin P Modak, Catherine N. Hogan, Ian W Hunter
    Abstract:

    A nonlinear, sliding mode adaptive controller was created for a needle-free Jet injection system. The controller was based on a simplified lumped-sum parameter model of the Jet-injection mechanics. The adaptive control scheme was compared to a currently-used Feed-forward+PID controller in both ejection of water into air, and injection of dye into ex-vivo porcine tissue. The adaptive controller was more successful in trajectory tracking and was more robust to the biological variations caused by a tissue load.

  • A needle-free technique for interstitial fluid sample acquisition using a lorentz-force actuated Jet Injector
    Journal of Controlled Release, 2015
    Co-Authors: Jean H. Chang, N. Catherine Hogan, Ian W Hunter
    Abstract:

    We present a novel method of quickly acquiring dermal interstitial fluid (ISF) samples using a Lorentz-force actuated needle-free Jet Injector. The feasibility of the method is first demonstrated on post-mortem porcine tissue. The Jet Injector is used to first inject a small volume of physiological saline to breach the skin, and the backdrivability of the actuator is utilized to create negative pressure in the ampoule and collect ISF. The effect of the injection and extraction parameters on sample dilution and extracted volumes is investigated. A simple finite element model is developed to demonstrate why this acquisition method results in faster extractions than conventional sampling methods. Using this method, we are able to collect a sample that contains up to 3.5% ISF in 3.1 s from post-mortem skin. The trends revealed from experimentation on post-mortem skin are then used to identify the parameters for a live animal study. The feasibility of the acquisition process is successfully demonstrated using live rats; the process is revealed to extract samples that have been diluted by a factor of 111-125.

  • The effect of Jet shape on Jet injection
    2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), 2015
    Co-Authors: Geehoon Park, Catherine N. Hogan, Ashin Modak, Ian W Hunter
    Abstract:

    The effects of the dispersion pattern of a needle-free Jet Injector are explored. The shape of the Jets were compared using a high-speed video camera and Jet injections of collimated and dispersed fluid Jets with a Lorentz-force actuated Jet Injector were made into acrylamide gel and post-mortem porcine tissue. A custom-built high-speed X-ray imaging system was used in order to observe the dynamics of the dispersion mechanism for each injection in real time. We show that a collimated Jet stream results in greater tissue penetration than a dispersed Jet stream.

Andrew Taberner - One of the best experts on this subject based on the ideXlab platform.

  • subcutaneous nicotine delivery via needle free Jet injection a porcine model
    Journal of Controlled Release, 2019
    Co-Authors: Bryan P. Ruddy, James W. Mckeage, Chris Bullen, Joanna Ting Wai Chu, Soo Hee Jeong, Bahareh Madadkhahsalmassi, Darren Svirskis, Malcolm D Tingle, Andrew Taberner
    Abstract:

    Subcutaneous delivery of nicotine was performed using a novel electrically-operated needle-free Jet Injector, and compared to hypodermic needle delivery in a porcine model. Nicotine was delivered as a single, one-milligram dose into the abdominal skin, formulated as a 50 microliter aqueous solution. Plasma levels of nicotine and cotinine, its main metabolite, were then monitored over 2 h, following which the injection site was excised for histological examination. No irritation or tissue damage were found at the injection sites, and the Jet-injected nicotine exhibited comparable absorption into the systemic circulation to that injected using a conventional needle and syringe. The needle-free Jet injection of nicotine is a promising and well tolerated method. The data presented from this porcine model will support a first in human trial towards a new promising nicotine replacement therapy.

  • Development and Performance of a Controllable Autoloading Needle-Free Jet Injector
    Journal of Medical Devices, 2013
    Co-Authors: Brian D. Hemond, Bryan Crane, Andrew Taberner, Ian W Hunter, C. Hogan, Hunter I W.
    Abstract:

    A Jet Injector platform technology that provides improved performance over existing Jet Injectors through the use of a controllable linear Lorentz-force actuator and software-based control system has been developed. Injectors designed on this platform are capable of delivering injections using arbitrary pressure pulse shaping. Pulse shaping has been shown to allow a wide degree of control over the depth to which the injection is delivered. A software-based Injector control system improves repeatability and allows for automatic reloading of the Injector, a task that would be difficult to implement using existing Jet Injector platforms. A design for a prototype autoloading controllable Jet Injector (cJI) based on this platform is detailed. The injection capability of this cJI was evaluated both in-vitro and in-vivo using a tissue analog, excised porcine tissue, and ovine tissue. An analysis of the cJI's performance indicates that this design is capable of delivering a controllable volume of fluid to a controllable depth based entirely on the parameter's input into the control software. DOI: 10.1115/1.4003330

  • A computational model of a controllable needle-free Jet Injector
    Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, EMBS, 2012
    Co-Authors: Rhys M. J. Williams, N. Catherine Hogan, Poul M. F. Nielsen, Ian W Hunter, Andrew Taberner
    Abstract:

    We present a mathematical model of the dynamics of a previously developed needle-free Jet Injector (NFJI) that is based upon a servo-controlled Lorentz-force motor. The Injector creates a fluid Jet that can pierce through the skin and deliver a drug to dermal, subcutaneous and muscular tissue. We use the model to predict the Jet speed achieved during an injection. The model simulates the electrical response of the motor coil, the mechanical response of the drug piston and ampoule and the friction incident upon the piston during the time course of the injection. High-speed video measurements of piston movement in response to a step input show that the model predicts piston-tip position during an injection within an RMS error of 287 m. The corresponding Jet speed is predicted to be 180 ms(-1) with a maximum overshoot to 205 ms(-1).

  • A portable needle-free Jet Injector based on a custom high power-density voice-coil actuator
    Annual International Conference of the IEEE Engineering in Medicine and Biology - Proceedings, 2006
    Co-Authors: Andrew Taberner, Nathan B. Ball, N. Catherine Hogan, Ian W Hunter
    Abstract:

    We have constructed a portable needle-free drug injection (NFI) device based upon a custom voice-coil linear actuator. Our actuator is optimized to provide high instantaneous force (>200 N) and power (4 kW) while still allowing a total stroke of 25 mm. The actuator is relatively inexpensive, compact, and lightweight, allowing it to serve as the force generator in a portable, reusable, handheld NFI system. The actuator is capable of accelerating liquid drug in quantities of up to 250 microL to a speed of more than 200 ms(-1). The repeatability of a 50 microL volume ejection is better than +/-1 microL.

Wolfgang Walther - One of the best experts on this subject based on the ideXlab platform.

  • her2 neu dna vaccination by intradermal gene delivery in a mouse tumor model gene gun is superior to Jet Injector in inducing ctl responses and protective immunity
    OncoImmunology, 2012
    Co-Authors: T Nguyenhoai, Wolfgang Walther, Peter M. Schlag, Dennis Kobelt, Oliver Hohn, Bernd Dörken, Steven Norley, Martin Lipp, Antonio Pezzutto, Jorg Westermann
    Abstract:

    DNA vaccines are potential tools for the induction of immune responses against both infectious disease and cancer. The dermal application of DNA vaccines is of particular interest since the epidermal and dermal layers of the skin are characterized by an abundance of antigen-presenting cells (APCs). The aim of our study was to compare tumor protection as obtained by two different methods of intradermal DNA delivery (gene gun and Jet Injector) in a well-established HER2/neu mouse tumor model. BALB/c mice were immunized twice with a HER2/neu-coding plasmid by gene gun or Jet Injector. Mice were then subcutaneously challenged with HER2/neu+ syngeneic D2F2/E2 tumor cells. Protection against subsequent challenges with tumor cells as well as humoral and T-cell immune responses induced by the vaccine were monitored. Gene gun immunization was far superior to Jet Injector both in terms of tumor protection and induction of HER2/neu-specific immune responses. After gene gun immunization, 60% of the mice remained tumor-free until day 140 as compared with 25% after Jet Injector immunization. Furthermore, gene gun vaccination was able to induce both a strong TH1-polarized T-cell response with detectable cytotoxic T-lymphocyte (CTL) activity and a humoral immune response against HER2/neu, whereas the Jet Injector was not. Although the disadvantages that were associated with the use of the Jet Injector in our model may be overcome with methodological modifications and/or in larger animals, which exhibit a thicker skin and/or subcutaneous muscle tissue, we conclude that gene gun delivery constitutes the method of choice for intradermal DNA delivery in preclinical mouse models and possibly also for the clinical development of DNA-based vaccines.

  • nonviral gene transfer for cancer gene therapy
    Xenotransplantation, 2008
    Co-Authors: Wolfgang Walther, Iduna Fichtner, Dennis Kobelt, Robert J Siegel, P Schlag, Ulrike Stein
    Abstract:

    Although the pre-clinical and clinical results of gene therapy have shown promise for some cancers, cancer gene therapy is still at an early stage of clinical development. Due to the complexity of targeted vector delivery to the tumor, our strategy for gene therapy is focussed on the development of local non-viral gene transfer to treat tumors. The local application of non-viral gene therapy is of particular value in the context of pre- or intraoperative application of therapeutic genes. This ensures accessibility of targeted tumor areas and will contribute to better local control of the disease. In this regard, applicable transfer technologies are needed in gene therapy. Different physical procedures, such as in vivo electroporation, sonoporation, ballistic transfer etc. are employed to deliver naked DNA into the target cells or tissues in vitro and in vivo. Among the various non-viral gene delivery technologies Jet-injection is gaining increasing acceptance, since this technique allows gene transfer into different tissues with deep penetration of naked DNA. The Jet-injection technology is based on low-volume Jets of high-velocity to penetrate skin and deeper tissues associated with efficient transfection of the affected area. For non-viral in vivo gene transfer a Jet-Injector prototype was created and tested. The beta-galactosidase (LacZ), green fluorescence protein reporter gene constructs were successfully Jet-injected into different syngeneic mouse and patient-derived xenotransplanted human tumor models of colon- or mammary carcinoma and malignant melanoma. Qualitative and quantitative expression analysis of Jet-injected tumor tissues revealed the efficient expression of these genes. Therapeutic in vivo experiments using the Jet-injection transfer of the cytosine deaminase suicide gene in tumors demonstrated antitumor effects with significant growth inhibition of the Jet-injected xenotransplanted colon carcinomas. Furthermore, Jet-injection was also successfully used for the application of a heat-inducible TNF-α expressing vector system leading to efficient in vivo tumor growth inhibition in the combined non-viral TNF-α gene transfer and hyperthermia approach. Based on our pre-clinical experiments for non-viral gene transfer, a phase I clinical trial has been conducted at the Clinic for Surgery and Surgical Oncology, Charite, Berlin to evaluate the feasibility, efficiency, and safety of Jet-injection aided LacZ-reporter gene transfer in patients with cutaneous metastases from breast cancer and malignant melanoma. In this study naked GMP-plasmid DNA was applied intratumorally by Jet-injection. The Jet-injection was well tolerated by all patients and no side effects have been experienced. The study clearly demonstrated that the single application of plasmid-DNA is safe and leads to the expression of the LacZ-reporter gene in the tumor tissue, as shown at mRNA- and at protein level.

  • Nonviral Jet-injection gene transfer for efficient in vivo cytosine deaminase suicide gene therapy of colon carcinoma.
    Molecular therapy : the journal of the American Society of Gene Therapy, 2005
    Co-Authors: Wolfgang Walther, Ulrike Stein, Iduna Fichtner, Dennis Kobelt, Jutta Aumann, Franziska Arlt, Peter M. Schlag
    Abstract:

    Jet-injection technology has developed into an efficient gene delivery system for nonviral in vivo gene transfer. In this study the Jet-Injector system was used for the intratumoral gene transfer of small volumes of naked DNA encoding the Escherichia coli cytosine deaminase (CD) suicide gene. In our in vivo studies human colon carcinoma (patient-derived tumor model Colo5734 and SW480 colon carcinoma)-bearing NMRI-nu/nu male mice received four Jet injections (10 microl per injection) of the CD-gene-carrying plasmid, representing 40 microg plasmid DNA per animal. Forty-eight hours after Jet-injection, treatment of tumors with 5-fluorocytosine (5-FC; 500 mg/kg ip) was started and during treatment tumor volumes were measured. Starting from day 5 of 5-FC treatment inhibition of tumor growth was seen in the CD-gene-transduced tumors compared to the respective control groups, which lasted for the entire observation time. Expression analysis at the mRNA and protein levels revealed efficient expression of the CD gene in the Jet-injected tumors. Therefore, in this in vivo study Jet-injection gene transfer of 40 microg CD-expressing naked plasmid DNA leads to a significant tumor growth inhibition. This study demonstrates the applicability of the Jet-injection technology for in vivo gene transfer into tumors to achieve efficient tumor gene therapy.

  • nonviral in vivo gene delivery into tumors using a novel low volume Jet injection technology
    Gene Therapy, 2001
    Co-Authors: Wolfgang Walther, Ulrike Stein, Iduna Fichtner, L Malcherek, Margit Lemm, P M Schlag
    Abstract:

    The Jet-injection technology has developed as an applicable alternative to viral or liposomal gene delivery systems. In this study a novel, low-volume, 'high-speed Jet Injector' hand-held system was used for the direct gene transfer of naked DNA into tumors. Lewis-lung carcinoma bearing mice were Jet-injected with the beta-galactosidase (LacZ), the green fluorescence (GFP) or the human tumor necrosis factor alpha (TNF-alpha) gene carrying vector plasmids. The animals received five Jet injections into the tumor at a pressure of 3.0 bar, delivering 3--5 microl plasmid DNA (1 microg DNA/microl in water) per single Jet injection. The Jet injection of DNA leads to a widespread expression pattern within tumor tissues with penetration depths of 5--10 mm. Analysis of tumor cryosections revealed moderate LacZ or GFP expression at 48 h and strong reporter gene expression 72 h and 96 h after Jet injection. The simultaneous Jet injection of the TNF-alpha and LacZ carrying vectors demonstrated efficient expression and secretion of both the cytokine, as well as LacZ expression within the tumor 24 h, 48 h, 72 h, 96 h and 120 h after Jet injection. These studies demonstrate the applicability of Jet injection for the efficient in vivo gene transfer into tumors for nonviral gene therapy of cancer using minimal amounts of naked DNA.

Jay W Hooper - One of the best experts on this subject based on the ideXlab platform.

  • A hantavirus pulmonary syndrome (HPS) DNA vaccine delivered using a spring-powered Jet Injector elicits a potent neutralizing antibody response in rabbits and nonhuman primates. Current gene therapy
    2016
    Co-Authors: Steven A Kwilas, Jennifer M Kishimori, Matthew Josleyn, Kurt Jerke, Michael Royals, John Ballantyne, Jay W Hooper
    Abstract:

    Abstract: Sin Nombre virus (SNV) and Andes virus (ANDV) cause most of the hantavirus pulmonary syndrome (HPS) cases in North and South America, respectively. The chances of a patient surviving HPS are only two in three. Previously, we demonstrated that SNV and ANDV DNA vaccines encoding the virus envelope glycoproteins elicit high-titer neutral-izing antibodies in laboratory animals, and (for ANDV) in nonhuman primates (NHPs). In those studies, the vaccines were delivered by gene gun or muscle electroporation. Here, we tested whether a combined SNV/ANDV DNA vaccine (HPS DNA vaccine) could be delivered effectively using a disposable syringe Jet injection (DSJI) system (PharmaJet, Inc). PharmaJet intramuscular (IM) and intradermal (ID) needle-free devices are FDA 510(k)-cleared, simple to use, and do not require electricity or pressurized gas. First, we tested the SNV DNA vaccine delivered by PharmaJet IM or ID devices in rabbits and NHPs. Both IM and ID devices produced high-titer anti-SNV neutralizing antibody responses in rabbits and NHPs. However, the ID device required at least two vaccinations in NHP to detect neutralizing antibodies in most ani-mals, whereas all animals vaccinated once with the IM device seroconverted. Because the IM device was more effective in NHP, the Stratis ® (PharmaJet IM device) was selected for follow-up studies. We evaluated the HPS DNA vaccine de-livered using Stratis ® and found that it produced high-titer anti-SNV and anti-ANDV neutralizing antibodies in rabbits (n=8/group) as measured by a classic plaque reduction neutralization test and a new pseudovirion neutralization assay. We were interested in determining if the differences between DSJI delivery (e.g., high-velocity liquid penetration through tis

  • a hantavirus pulmonary syndrome hps dna vaccine delivered using a spring powered Jet Injector elicits a potent neutralizing antibody response in rabbits and nonhuman primates
    Current Gene Therapy, 2014
    Co-Authors: Steven A Kwilas, Jennifer M Kishimori, Matthew Josleyn, Kurt Jerke, Jack Ballantyne, Michael Royals, Jay W Hooper
    Abstract:

    Sin Nombre virus (SNV) and Andes virus (ANDV) cause most of the hantavirus pulmonary syndrome (HPS) cases in North and South America, respectively. The chances of a patient surviving HPS are only two in three. Previously, we demonstrated that SNV and ANDV DNA vaccines encoding the virus envelope glycoproteins elicit high-titer neutralizing antibodies in laboratory animals, and (for ANDV) in nonhuman primates (NHPs). In those studies, the vaccines were delivered by gene gun or muscle electroporation. Here, we tested whether a combined SNV/ANDV DNA vaccine (HPS DNA vaccine) could be delivered effectively using a disposable syringe Jet injection (DSJI) system (PharmaJet, Inc). PharmaJet intramuscular (IM) and intradermal (ID) needle-free devices are FDA 510(k)-cleared, simple to use, and do not require electricity or pressurized gas. First, we tested the SNV DNA vaccine delivered by PharmaJet IM or ID devices in rabbits and NHPs. Both IM and ID devices produced high-titer anti-SNV neutralizing antibody responses in rabbits and NHPs. However, the ID device required at least two vaccinations in NHP to detect neutralizing antibodies in most animals, whereas all animals vaccinated once with the IM device seroconverted. Because the IM device was more effective in NHP, the Stratis® (PharmaJet IM device) was selected for follow-up studies. We evaluated the HPS DNA vaccine delivered using Stratis® and found that it produced high-titer anti-SNV and anti-ANDV neutralizing antibodies in rabbits (n=8/group) as measured by a classic plaque reduction neutralization test and a new pseudovirion neutralization assay. We were interested in determining if the differences between DSJI delivery (e.g., high-velocity liquid penetration through tissue) and other methods of vaccine injection, such as needle/syringe, might result in a more immunogenic DNA vaccine. To accomplish this, we compared the HPS DNA vaccine delivered by DSJI versus needle/syringe in NHPs (n=8/group). We found that both the anti-SNV and anti-ANDV neutralizing antibody titers were significantly higher (p-value 0.0115) in the DSJI-vaccinated groups than the needle/syringe group. For example, the anti-SNV and anti-ANDV PRNT50 geometric mean titers (GMTs) were 1,974 and 349 in the DSJI-vaccinated group versus 87 and 42 in the needle/syringe group. These data demonstrate, for the first time, that a spring-powered DSJI device is capable of effectively delivering a DNA vaccine to NHPs. Whether this HPS DNA vaccine, or any DNA vaccine, delivered by spring-powered DSJI will elicit a strong immune response in humans, requires clinical trials.

Ulrike Stein - One of the best experts on this subject based on the ideXlab platform.

  • nonviral gene transfer for cancer gene therapy
    Xenotransplantation, 2008
    Co-Authors: Wolfgang Walther, Iduna Fichtner, Dennis Kobelt, Robert J Siegel, P Schlag, Ulrike Stein
    Abstract:

    Although the pre-clinical and clinical results of gene therapy have shown promise for some cancers, cancer gene therapy is still at an early stage of clinical development. Due to the complexity of targeted vector delivery to the tumor, our strategy for gene therapy is focussed on the development of local non-viral gene transfer to treat tumors. The local application of non-viral gene therapy is of particular value in the context of pre- or intraoperative application of therapeutic genes. This ensures accessibility of targeted tumor areas and will contribute to better local control of the disease. In this regard, applicable transfer technologies are needed in gene therapy. Different physical procedures, such as in vivo electroporation, sonoporation, ballistic transfer etc. are employed to deliver naked DNA into the target cells or tissues in vitro and in vivo. Among the various non-viral gene delivery technologies Jet-injection is gaining increasing acceptance, since this technique allows gene transfer into different tissues with deep penetration of naked DNA. The Jet-injection technology is based on low-volume Jets of high-velocity to penetrate skin and deeper tissues associated with efficient transfection of the affected area. For non-viral in vivo gene transfer a Jet-Injector prototype was created and tested. The beta-galactosidase (LacZ), green fluorescence protein reporter gene constructs were successfully Jet-injected into different syngeneic mouse and patient-derived xenotransplanted human tumor models of colon- or mammary carcinoma and malignant melanoma. Qualitative and quantitative expression analysis of Jet-injected tumor tissues revealed the efficient expression of these genes. Therapeutic in vivo experiments using the Jet-injection transfer of the cytosine deaminase suicide gene in tumors demonstrated antitumor effects with significant growth inhibition of the Jet-injected xenotransplanted colon carcinomas. Furthermore, Jet-injection was also successfully used for the application of a heat-inducible TNF-α expressing vector system leading to efficient in vivo tumor growth inhibition in the combined non-viral TNF-α gene transfer and hyperthermia approach. Based on our pre-clinical experiments for non-viral gene transfer, a phase I clinical trial has been conducted at the Clinic for Surgery and Surgical Oncology, Charite, Berlin to evaluate the feasibility, efficiency, and safety of Jet-injection aided LacZ-reporter gene transfer in patients with cutaneous metastases from breast cancer and malignant melanoma. In this study naked GMP-plasmid DNA was applied intratumorally by Jet-injection. The Jet-injection was well tolerated by all patients and no side effects have been experienced. The study clearly demonstrated that the single application of plasmid-DNA is safe and leads to the expression of the LacZ-reporter gene in the tumor tissue, as shown at mRNA- and at protein level.

  • Nonviral Jet-injection gene transfer for efficient in vivo cytosine deaminase suicide gene therapy of colon carcinoma.
    Molecular therapy : the journal of the American Society of Gene Therapy, 2005
    Co-Authors: Wolfgang Walther, Ulrike Stein, Iduna Fichtner, Dennis Kobelt, Jutta Aumann, Franziska Arlt, Peter M. Schlag
    Abstract:

    Jet-injection technology has developed into an efficient gene delivery system for nonviral in vivo gene transfer. In this study the Jet-Injector system was used for the intratumoral gene transfer of small volumes of naked DNA encoding the Escherichia coli cytosine deaminase (CD) suicide gene. In our in vivo studies human colon carcinoma (patient-derived tumor model Colo5734 and SW480 colon carcinoma)-bearing NMRI-nu/nu male mice received four Jet injections (10 microl per injection) of the CD-gene-carrying plasmid, representing 40 microg plasmid DNA per animal. Forty-eight hours after Jet-injection, treatment of tumors with 5-fluorocytosine (5-FC; 500 mg/kg ip) was started and during treatment tumor volumes were measured. Starting from day 5 of 5-FC treatment inhibition of tumor growth was seen in the CD-gene-transduced tumors compared to the respective control groups, which lasted for the entire observation time. Expression analysis at the mRNA and protein levels revealed efficient expression of the CD gene in the Jet-injected tumors. Therefore, in this in vivo study Jet-injection gene transfer of 40 microg CD-expressing naked plasmid DNA leads to a significant tumor growth inhibition. This study demonstrates the applicability of the Jet-injection technology for in vivo gene transfer into tumors to achieve efficient tumor gene therapy.

  • nonviral in vivo gene delivery into tumors using a novel low volume Jet injection technology
    Gene Therapy, 2001
    Co-Authors: Wolfgang Walther, Ulrike Stein, Iduna Fichtner, L Malcherek, Margit Lemm, P M Schlag
    Abstract:

    The Jet-injection technology has developed as an applicable alternative to viral or liposomal gene delivery systems. In this study a novel, low-volume, 'high-speed Jet Injector' hand-held system was used for the direct gene transfer of naked DNA into tumors. Lewis-lung carcinoma bearing mice were Jet-injected with the beta-galactosidase (LacZ), the green fluorescence (GFP) or the human tumor necrosis factor alpha (TNF-alpha) gene carrying vector plasmids. The animals received five Jet injections into the tumor at a pressure of 3.0 bar, delivering 3--5 microl plasmid DNA (1 microg DNA/microl in water) per single Jet injection. The Jet injection of DNA leads to a widespread expression pattern within tumor tissues with penetration depths of 5--10 mm. Analysis of tumor cryosections revealed moderate LacZ or GFP expression at 48 h and strong reporter gene expression 72 h and 96 h after Jet injection. The simultaneous Jet injection of the TNF-alpha and LacZ carrying vectors demonstrated efficient expression and secretion of both the cytokine, as well as LacZ expression within the tumor 24 h, 48 h, 72 h, 96 h and 120 h after Jet injection. These studies demonstrate the applicability of Jet injection for the efficient in vivo gene transfer into tumors for nonviral gene therapy of cancer using minimal amounts of naked DNA.